Lace Weight yarns may also include some fingering weight yarns and threads. They have a gauge range of 33-40 stitches per 4" in stockinette stitch, generally using US000 (1.5mm) to US1 (2.5mm) needles.Category 0 in the standard yarn weight system.

Lace weight yarns are usually knitted on larger needles to create lacy openwork patterns. Accordingly a gauge range is difficult to determine.
Always follow the gauge stated in the pattern.

Double Knitting weight yarns may also include some light worsted weight yarns. They have a gauge range of 21-24 stitches per 4" in stockinette stitch, generally using US5 (3.75mm) to US7 (4.5mm) needles.Category 3 in the standard yarn weight system.